Since the current objective is to simulate flights in the International Space Station (3 to 6 months) or possible flights to Mars (500 to 1000 days), it is mandatory to extend the duration of the simulation experiments. This is why three Space Agencies, CNES (France), European Space Agency (ESA, European Union), National Space Development Agency of Japan (NASDA, Japan) decided to join forces and undertake in common such simulation campaigns on ground, to best apprehend the adaptation processes to the constraints of the space environment.